Being Bilingual Protects Against Age-Related Cognitive Changes

According to a study, bilingualism or being fluent in two languages may help "prevent some of the cognitive decline seen in same-age monolingual speaking persons." The findings of this study appears in the Journal of Psychology and Aging (June 2004), the press release of which appears on APA.org.

Lead author Ellen Bialystok, Ph.D., of York University said that "crystallized intelligence" or learned knowledge and habitual procedures endure as people get older, but that fluid intelligence or abilities that depend on keeping an individual’s attention on a task decline with age.

However, Bialystok found that individuals who have been bilingual for most of their life were "better able to manage their attention to more complex set of rapidly changing demands."

Bialystok and her team were able to gauge this by using the experimental "Simon Task" which distracts the test takers on purpose.

The Simon Task

The Simon Task, according to the press release, "measures individual’s reaction time without the subjects having to be familiar with the content, and it measures aspects of cognitive processing that decline with age, the study reports." The participants watched squares flash on a computer monitor and were told to press a certain color key once they saw a square in a specific area of the monitor.

Half of the squares flashed on the same side of the computer monitor where the right key was located (congruent trials). The other half came up on the opposite side of the monitor where the right key was (incongruent trials).

Also, to find out if speed was key in responding correctly in the tasks, the researchers included a "set of conditions that raised the number of different stimuli from two to four flashing squares."

The participants

Comparing the results of three studies involving 104 monolingual and bilingual individuals aged 30 to 50 years old, and 50 older adults, aged 60 to 88 years old who took the "Simon Task," the researchers found that the bilingual individuals responded faster, even when the added stimuli were were flashed in the middle of the screen, and "involved no interference from incongruent spatial position information."

The researchers also used a control condition which showed two flashing squares (two stimuli) in the middle of the computer monitor, but it created no difference in the subjects’ reaction time, which eliminates overall speed advantage as the reason behind the performance differences between the bilingual and the monolingual groups.

Adult monolingual and bilingual participants were matched on background experiences and "cognitive measures performed differently on the Simon task" in all three studies.

Results of the study

Both younger and older adult bilingual participants were faster than their monolingual counterparts in both congruent and incongruent trials. They were also less distracted by the added stimuli or "incongruent items" regardless of speed. Significantly, being bilingual lowered age-related rise in distractibility, or what the researchers call the Simon effect, suggesting that a lifetime of managing two languages "attenuates the age-related decline in the efficiency of inhibitory processing."

All the bilingual participants in the study used two languages everyday since age 10.

The researchers suggest that the same cognitive control processes are used when when attending to a stimulus "while ignoring irrelevant location information" and when using two languages.

The authors therefore conclude that bilingualism provides an wide range of benefits "across a range of complex cognitive tasks."